Scans_Daily

He acted in cold blood when killing the Pocket Universe Kryptonians. And he didn't particularly look like the mind control was driving him to uncontrollable rage in this scene; rather, he became enraged as a reaction to what the mind control was making him see.

Of course there were other solutions, Diana's acting like an idiot too here. But Superman's not particularly suggesting any of them, and his "thou shall not kill no matter what" attitude just isn't consistent with his past behavior. He's never been as judgey about other people killing as he is about doing it himself.